Over the years I've bought extended warranties for 3 of my motorcycles, and a '99 Valkyrie I bought used had a few years remaining. On those 4 bikes I only used the extended warranty one time, even though one of the bikes, my '98 Valkyrie, ran over 100,000 miles before the warranty expired. And, the single warranty claim was to replace a leaky radiator cap. So I'd say they weren't a very good investment for me.
I've bought them for 2 cars and a truck as well. I've used them a few times, but not once did the cost of repairs exceed the cost of the warranty. The main reason I buy them is that when I have the warranty I get any problem fixed right away, rather than putting it off thinking I'll get around to doing it myself.
Whatever you do, shop around! The dealer markup on extended warranties is huge, like 100%. That price from Max's Cycle looks great, and is tempting me to get one.
FYI if anyone is considering one for a Ford, there's a dealer in Minnesota that sells the factory 'ESP' warranties for their cost plus $100 for processing. I ended up paying about half of what my dealer wanted to charge.